The present invention relates to electrical cable and particularly to ribbon cables in which insulated conductors are positioned, in a fixed relationship to each other, and more particularly, to transposed ribbon cables and methods and apparatus for manufacturing the same.
Electrical cables in a variety of configurations have been available for an extended period of time. One of those varieties is ribbon cable. A ribbon cable has a roughly rectangular cross section as opposed to the round cross section of ordindary cables. The rectangular cross section permits use of the ribbon cable and applications where one or two dimensions are constrained.
Ribbon cables also provide improved field or armature and stator windings in a number of electrical magnetic devices such as motors and generators and transformers. Ribbon cables in many applications provide for increased ease of assembly and improved efficiency. In some electromagnetic devices, eddy current losses can be reduced drastically by use of transposed ribbon cable. In other electromagnetic devices these eddy current losses can be balanced against other losses to produce an electromagnetic device having a greatly improved efficiency.
In transformer design, greater energy efficiency is achieved by using ribbon cable. Load losses can be reduced by using transposed ribbon cable. Similar benefits and similar energy efficiencies can be achieved in rotating electromagnetic device design using ribbon cables and transposed ribbon cables.
Further, transposed cables heretofore have been limited as to the number of conductors in the cable. This limitation is the result of conventional methods and apparatus for manufacturing transposed cable. No such limitation exists for the methods and apparatus of the invention.
It is therefore, however, desirable to provide an improved method and apparatus for manufacturing transposed ribbon cable in which the insulated conductors are in a fixed relation to each other and are at an angle to the longest dimension of the cable.